Pneumatic tool



E. W. BALL PNEUMATIC TOOL .I uly 5, 1,938.

Filed March l5, 1957 Patented July 5, 1938 PNEUMATIC Tool.

Eldon W. Ball, Barre, Vt., assignor to Rock of Ages Corporation, Barre,Vt., a corporation of Vermont 1 Claim.

This invention relates to pneumatic tools, such as hammers, used infacing andA carving stone and in other similar operations. When suchtools are used on stone, a large amount of dust and many particles ofgrit are set free and must be collected and removed to avoid harm to theeyes or lungs of the operator. Satisfactory removal of this dust andgrit has proved a troublesome problem.

Itis the general object of my invention to provide improved andsimplified means for collecting and eifectively removing such dust andgrit or other fine material, without interfering with the convenient useofthe tool.

To the accomplishment of this object, I preferably provide a suctiondevice which is incorporated with a pneumatic tool and which is easilyshiitable therewith. In the preferred form, the suction device ismounted concentric with the tool and encloses the cutting tool.

My invention further relates to arrangements and combinations of partswhich will be hereinafter described and more particularly pointed out inthe appended claim.

25 A preferred form of the invention is shown in the drawing, in whichFig. 1 is a sectional side elevation of a pneumatic tool embodying myimprovements;

Figs. 2, 3, 4 and 5 are sectional plan views, taken along the lines 2 2,3 3, 4 4 and 5 5 in Fig. 1 respectively;

Figs. 6 and 1 are partial sectional elevations, taken along the lines 66 and 1 1 in Fig. 3 respectively; and 35 Fig. 8 is a partial sideelevation of my improved tool.

Referring to the drawing, I have shown my invention embodied in apneumatic tool comprising a piston or hammer Ill verticallyreciprocating in 40 a cylinder II which is closed at its upper end by aplug I2. The cylinder II is provided with a plurality of longitudinallyextending external ribs I3 (Fig. 3) enclosed by a casing I4.

Pressure passages IE extend longitudinally in the ribs I3 and areconnected by ports I1 to the cylinder Il. At their upper ends thepressure passages I6 are connected to a central pasy sage lil (Fig. 6)in the plug I2. A hose connection 2t (Fig. l) is threaded in the upperend of the plug I2 and is adapte-d to receive a hose 22 through whichair under pressure is supplied from any suitable source to the passagesI6 and cylinder I I.

Suction passages 25 are formed between the ribs I3, as clearly shown inFig. 3, and these suc- Application March 15, 1931, Serial No. 130,969

(Cl. Z55-50) tion passages: connect at their upper ends with a commonsuction passage 21 in a hose connection 28, which connection is securedto the upper end of the casing I4 by an interposed threaded sleeve 29.

A suction hose is secured to the connection 28 as indicated in Fig. 1,said hose being preferably concentric with the pressure hose 22 andenclosing the same but being of substantially greater diameter than thehose 22. Exhaust ports 10 33 (Figs. 3 and '1) connect the cylinder I Ito the suction passages 25. At their lower ends the suction passages 25connect into an annular suction passage 35 formed in a reduced lowerportion or extension 36 of the casing member I4. 15

A chisel or other tool C is loosely mounted in a downward extension 31of the cylinder II, which extension forms the inner wall of the annularsuction passage 35. A suction head 40 (Figs. l and 8) preferably ofrubber, is mounted on a 20 sleeve 4I, the upper portion of which is aquarter turn elliptical t in the lower end of the annular passage 35 inthe casing extension 36.

While I have sho-wn certain parts of the hammer mechanism, thismechanism in itself forms no part of my present invention and it isunnecessary to describe the same in further detail, beyond stating thatthe hammer operates in the usual manner to apply rapidly repeated blowsto the upper end of the chisel or tool C. 30

When the hammer is thus operated, the chisel is driven repeatedlyagainst the stone, producing a large amount of dust and grit. This loosematerial is immediately drawn into the suction head 40 and upwardthrough the annular passage 35, the longitudinal passages 25 and thecommon upper passage 21 to the suction pipe 30, through which the dirtand grit is remove-d to a suitable point of discharge. At the same timethe pipe 30 receives and discharges the exhaust air from the cylinder II through the exhaust ports 33.

The lower end of the suction head 40 is preferably spaced above the workW sufciently to permit the operator to see the work and to manuallyguide the chisel in a normal manner.

Having thus described my invention and the advantages thereof, I do notwish to be limited to the details herein disclosed, otherwise than asset forth in the claim, but what I claim is:

A portable pneumatic hammer of the type adapted for surface nishing andcarving operations on blocks of stone characterized by the provision ofa cylindrical body for said hammer having a plurality of spacedlongitudinally extending external ribs, a casing surrounding saidcylinder and held in concentric spaced relation therewith by said ribs,thereby providing a plurality of longitudinally extending segmentalsuction passages, direct exhaust connections within said casing fromsaid cylinder to said suction passages, a pressure tube connected tosupply air to said cylinder, a suction tube concentric with andsurrounding said pressure tube and connected with said suction passages,and a suction head secured to and concentric with the lower end of saidcasing and surrounding the hammer adjacent the work, said suction headbeing in direct communication with said suction passages and beingthereby rendered effective to collect and remove dust Vfrom the stonesurface being finished or carved by use of said hammer.

ELDON W. BALL.

